I have encountered this black-colored growth on onion skins a lot. It seems to develop over the course of weeks and I have rarely, if ever, encountered the material on fresh ones. If I peel the onion ...

In microbiology we have two types of microbial diagnosis. The direct method is where we detect the invader's DNA, Antigens or culture to see the exact pathogen while the second, indirect, method is ...

Background : B.thuringiensis produces an inactive crystalline toxin during sporulation which when ingested by an insect, gets activated and causes pore formation in gut , subsequently leading to death ...

Can both heterotrophic and autotrophic organism survive in anaerobic conditions? If an autotrophic organism does not produce carbon dioxide but requires oxygen, it should not be present in anaerobic ...

I've been preparing wet slides for my kids to look at from pond water. I have a mason jar of pond water. What can I do to keep the microbes in the jar alive going forward so that we can look at it any ...

I've read that the bacterial capsule protects the bacterium from phagocytes and prevents water (and nutrients, possibly?) leakage from the bacterium.
A less organized and less dense version is called ...

Last year I read a course in biology. During that course I learnt that Protozoa like Lamblia intestinalis or Entamoeba hystolitica form cysts in unfavourable conditions.
This year I read a course in ...

Methyl-alcohol is the weakest alcohol in terms of bactericidal properties. However, I have read that it also works as sporicide.
What is the effectiveness of methyl-alcohol in killing the spores of ...

What can cause an erythematous, fluctuant, nontender mass in the middle of the neck?
Full Case Study: (Its the last of 6 cases and I just can't figure this one out, because of all the possibilities, ...

I'm studying microbiology right now and I have come across something confusing to me. I thought electrons provided energy to the cell by being incorporated into reducing powers and eventually driving ...

We are regularly doing bacterial transformation and subculture from plate to liquid media to extract DNA. This usually goes very well and is straightforward, but occasionally, the colonies that grew ...

What I learned in class:
Normally chocolate agar is needed to grow Haemophilus and Neisseria. The Staph streak technique can be used for culturing Haemophilus on blood agar by allowing the Staph to ...

I'm reading this paper about transmissible cancer cells in clams (Metzger et al. 2015) and I was wondering if there are any single-cellular organisms that are around today that are suspected as having ...

Most microalgae have rigid cell walls.
Dunaliella Salina is a pretty famous example of an algae with no cell wall, but just a plasma membrane.
Are there any other microalgae without a cell wall?. I ...

So, the HIV-1 jump to humans occurred as early as the 1920s, but the AIDS epidemic didn't start until the early 1980s.
Some things I don't understand about this:
Why the delay?
What is needed for a ...

I understand the different ways bacteria can undergo horizontal gene transfer (transformation, transduction (phages), conjugation (plasmids)).
Is there an experimental method to tell how a specific ...

I am researching a way to monitor the membrane damage of cells. To do that I fist have to have reference points, namely, cells with damaged membranes.
I am working with Dunalliela, Hematococcus (both ...

Not all bacteria have acquired F-plasmids through conjugation. Some of the mechanisms for this are unsuccesful conjugation events (mechanical disruption), no transfer due to integration in bacterial ...

I'm currently sick because of scarlet fever but I got treated with antibiotics. I know that after 1.5 day using antibiotics the streptococci I release at home are dangerous anymore. But my question ...

The gram positive have negative components in the peptidoglycan layer in the form of teichoic acid phosphodiester bonds, and the gram negative have negative components in their outer membrane in the ...

If plasmids are important for bacteria to express specific genes under stressful conditions, why are these genes not already incorporated into their chromosome to begin with? What is the evolutionary ...